Control Room with problematic ceiling

Hello everybody, I am planning my studio that will be located in Milan, Italy. I have a quite good experience in building stuffs especially with wood. The goal is to have a decent sounding control room that will be used for sound design. My main focus is not to record here but instead to listen. I will use a stereo setup. The place is located on the basement of a big building with only office on the ground and first floor, then noise is not a problem during the night, and during the day they do not care. The wall are really thick anyway and then noise is not a problem here. The problem I got is the ceiling of this basement that unfortunately is a barrel vault, but is not too strong, as you will see on the following images. The length of the room is fixed and can not be changed and is '455 cm' , the width at the moment is '400 cm' but eventually I could move this wall in order to make it a maximum of '420 cm' or shorter. The height is at the center of the vault '370 cm' and it starts after '270 cm' of linear wall. There are also two cavity in the walls, as you can see in the pictures. My Budget is from around 600$ and I could eventually arrive to 1000$ in case there would be a big improvement. This should also include other treatments. I sorted that the ideal dimensions of the room would be 295 height x 377 width x 455 length, giving then a ratio of 1 : 1.28 : 1.54, as the one given by Sepmeyer. The problem is anyway that I should change the width, even if calculating the room modes using this calculator ( http://www.bobgolds.com/Mode/RoomModes.htm ) did not give bad results for a 400 cm width. At the same time the ceiling is not 295, instead is different for the whole room. My solution would be to hang from the ceiling few acoustic absorber as illustrated in a preview. What do you think? Is this room going to sound awful? How would you treat it? I will treat the studio also in other ways but before proceeding in elaborating bass traps and other treatment I would like to sort it out the ceiling problem and the dimensions. I read the topic about the instructions and I tried to follow them sorry if I missed something. Thanks, Babs

welcome! one option is to build up some heavy solid backed clouds to shape the front of the room. populate the curved overhead with hanging broadband absorbers to nullify the effects of the curve. on the back of the room ceiling - smaller absorbers hung down. in the (window?) cavities, fill with insulation for absorption and consider some saw tooth slats along the front and back walls. some additional scattered absorbers on the side walls. - can you post the SU model?

Hey, Thanks for the answer! I have some news about this studio because it will be bigger. I will use now the whole space that is 7.55m long. I will post a SU model ASAP.

After the summer time I am starting to build the studio, but the dimensions will not change as stated before. :? I am posting here the SU model in order to help you helping me :| . http://www.sendspace.com/file/i1pgb0 Unfortunately it was too big to upload it here, even as .zip The dimensions on the previous images were not perfect, but the ones on the model are the right ones. I decided to include also a new photo just for you to have an idea before downloading the model. What do you think about using the cavity at the back as a bass trap? And the small cavity on one of the corners? Thanks, Babs

Hello, I did some plan with treatment and I would like to listen some of your thoughts about it. I am including here the SU file, as usual is too big to upload it here then I will use send space (if you know any better option please let me know). http://www.sendspace.com/file/31r15z The photo above show the project as well. I have some questions also on my design: - What type of wood do I have to use for the slat resonator in the front? - Do you think I should use for corners SuperChunk or a bass trap panel? - Regarding the cloud what do you think is the best distance from the ceiling in my case? - I have a sliding door that in theory should go on the back of the corner trap, do you think that it would work? Thanks!

- What type of wood do I have to use for the slat resonator in the front?

What slat resonator? I don't see anything on your diagram that looks like a slot resonator.

- Do you think I should use for corners SuperChunk or a bass trap panel?

In the corners, I would use only Superchunks. If you also need panel resonators, they should go against the walls, never in the corners. Panel traps are pressure-based devices, which means they must go where the pressure nodes are in the room. While it is true that pressure nodes are present in the corners, it is physically impossible to get a large enough panel trap into a corner, so the next best place is flat against the wall, at the pressure node of the specific mode that is causing problems. So superchunks are better in corners.

- I have a sliding door that in theory should go on the back of the corner trap, do you think that it would work?

It should be fine. Just mount the superchunk module on wheels, so you can roll it out of the way when you need to. But I don't see that sliding door marked on your Sketchup: Where is it? One other comment: I would not use QRD diffusers on the first reflection points in a small room like that! They are way too close to your ears and to the speakers. Either angle the walls for an RFZ design (or maybe used angled slot walls), or put thick absorption spaced away from the walls at the first reflection points. Your front-most cloud also seems to be angled too much, and is too close to the front wall, to be properly treating your first reflection area above the console. I'd suggest that you bring that more directly over the console and angle it better. - Stuart -

First of all, thanks for the answer!

Soundman2020 wrote:

- What type of wood do I have to use for the slat resonator in the front?

What slat resonator? I don't see anything on your diagram that looks like a slot resonator.

Sorry I meant slot resonator, it is the treatment at the back of the room in front of the cavity. I took the design from [ http://www.johnlsayers.com/HR/index1.htm ] . Because it is at the center I thought of swapping one of the two inclined parts showed in johnlsayers design. Is it wrong?

Soundman2020 wrote:

- Do you think I should use for corners SuperChunk or a bass trap panel?

In the corners, I would use only Superchunks. If you also need panel resonators, they should go against the walls, never in the corners. Panel traps are pressure-based devices, which means they must go where the pressure nodes are in the room. While it is true that pressure nodes are present in the corners, it is physically impossible to get a large enough panel trap into a corner, so the next best place is flat against the wall, at the pressure node of the specific mode that is causing problems. So superchunks are better in corners.

I saw the solution of placing a pannel in Ethan's site [ http://www.ethanwiner.com/acoustics.html ] but is not a problem for me to change it with Superchunk as you will see in the new project.

Soundman2020 wrote:

- I have a sliding door that in theory should go on the back of the corner trap, do you think that it would work?

It should be fine. Just mount the superchunk module on wheels, so you can roll it out of the way when you need to. But I don't see that sliding door marked on your Sketchup: Where is it?

I thought it would be clear enough where is the sliding door also looking at the previous images, but I was wrong! :? I wrote in the new plant where it is placed I hope it is clear now. Anyway mounting the Superchunk on wheels seems like a cool idea!

Soundman2020 wrote:

One other comment: I would not use QRD diffusers on the first reflection points in a small room like that! They are way too close to your ears and to the speakers. Either angle the walls for an RFZ design (or maybe used angled slot walls), or put thick absorption spaced away from the walls at the first reflection points. Your front-most cloud also seems to be angled too much, and is too close to the front wall, to be properly treating your first reflection area above the console. I'd suggest that you bring that more directly over the console and angle it better.

I changed my design following your directions, what do you think? New SU Project download link: http://www.sendspace.com/file/lruqbj The Superchunk is 32" is that enough? Would you use in my case what kind of fiberglass 703 or 705 kind? THANKS! babs

Babs - you need to be more drastic in your treatment in such a small room. try something like this:

Because it is at the center I thought of swapping one of the two inclined parts showed in johnlsayers design. Is it wrong?

I think I'd rather go with deep absorption on the rear wall, and slot walls on the side. You are still showing large QRD diffusers on the side walls of your room: I wouldn't do that in a small room.

The Superchunk is 32" is that enough? Would you use in my case what kind of fiberglass 703 or 705 kind?

I'd use 703 for that. And two 32" superchunks in the corners is a good start, but the room is small so it will need more than that. - Stuart - Edited to add: Sorry John. Didn't see your post! :oops: "Babs - you need to be more drastic in your treatment in such a small room. try something like this:" Now THAT makes a whole lot of sense!